This invention relates to a power window actuator and particularly to a power window actuator for a swingably or pivotally mounted window such as a rear side vent or corner window of a motor vehicle such as a van.
It is desirable to provide a powered rear side vent window for ventilation purposes in vehicles, particularly vans and minivans. These rear side vent windows are generally swingably mounted and open outwardly in the vehicle body and are typically remotely activated as, for example, from the driver""s seat.
Several types of vehicle power vent window actuators are known and used. Whereas these prior art actuators are generally satisfactory, they typically suffer from one or more disadvantages. Specifically, the prior art actuators are relatively expensive and/or overly large and/or are relatively noisy in operation.
This invention is directed to an improved vent window actuator.
More specifically, this invention is directed to a vent window actuator that is inexpensive, quiet in operation, and compact.
The actuator of the invention is of the type including a housing, an electric motor mounted on the housing, a pivot arm mounted on the housing and adapted to be connected to the vent window to effect opening and closing movement of the vent window in response to pivotal movement of the pivot arm, and a drive mechanism interconnecting the output of the motor and the pivot arm and operative in response to energization of the motor to pivot the pivot arm and move the vent window.
According to the invention, the drive mechanism comprises a first worm driven by the motor, a first worm wheel driven by the first worm, a second worm driven by the first worm wheel, and a second worm wheel driven by the second worm and driving the pivot arm. This arrangement, employing two successive worm drives, provides the quiet operation inherent in a worm drive and, by virtue of the speed reduction achieved utilizing the successive worm drives, allows the use of a smaller, less expensive motor.
According to a further feature of the invention, the first worm wheel is formed of a plastic material. This choice of material, which is made possible by the fact that the back drive loading imposed on the actuator is largely absorbed by the second worm drive, allows the cost of the actuator to be further reduced by virtue of the relatively inexpensive plastic material of the first worm wheel.
According to a further feature of the invention, the actuator further includes a coil spring mounted on the housing proximate the second worm wheel and operative to assist the second worm wheel in generating a sealing force sufficient to positively seal the vent window against the window seal of the motor vehicle. This arrangement allows the actuator to satisfy even very high window sealing requirements irrespective of the use of a relatively small, low power motor.
According to a further feature of the invention, the drive mechanism comprises a first shaft extending coaxial with the motor output and driven by the motor, a second shaft driven by the first shaft and extending perpendicular to the first shaft, and a third shaft extending perpendicular to the first and second shaft, driven by the second shaft, and driving the pivot arm. These three drive shafts arranged in a mutually perpendicular or cross relationship facilitate the compact packaging of the drive mechanism of the actuator and ensure a robust and smooth transmission of power from the motor to the pivot arm.
According to a further feature of the invention, the motor includes a hub at one end thereof and an output shaft at another end thereof; the first worm is mounted on the output shaft; the housing includes a cavity, a first saddle proximate one end of the cavity, and a second saddle proximate another end of the cavity; and the motor is mounted in the cavity with a free end of the output shaft journaled in the first saddle and the motor hub seated in the second saddle. This arrangement allows a firm, positive mounting of the motor in the housing whereby to eliminate motor wobble and consequent excessive wear in the drive mechanism.